X0101 EFFECT 33 LIVE 2014-03-31 0000894189-14-001436 485APOS 0001505064 MainGate Trust 333-170422 S000031058 MainGate MLP Fund C000096312 Class A S000031058 MainGate MLP Fund C000096313 Class I S000031058 MainGate MLP Fund C000142071 Class C